(a) Field of the Invention
The present invention relates generally to a lifting jack and more particularly, to a lifting mechanism and spacer block arrangement for use in a hydraulic/air lifting jack.
(b) Description of the Prior Art
When wishing to lift a load, for example, a machine, lathe, construction, etc., or to support a first member on a second member at the desired pitch, a small hydraulic/air lifting jack may be used. A small hydraulic/air lifting jack is highly movable, however it has a limited lifting stroke. When lifting a load, the user may have to operate the hydraulic/air lifting jack to lift the load to the desired elevation through several lifting stokes. Further, after each lifting stroke during a lifting operation, a respective movable support block is used to support the load in position and a spacer block is inserted under the lifting mechanism of the hydraulic/air lifting jack so that the lifting mechanism of the hydraulic/air lifting jack can be operated to lift the load again. If the spacer block in use can not be positively maintained in position, the load and the lifting mechanism may fall, thereby resulting in an accident.